UA140082U - METHOD OF CRYPTOGRAPHIC TRANSFORMATION OF INFORMATION - Google Patents

Abstract

The method of cryptographic transformation of information is that the bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes). As an S-block, a variable three-dimensional matrix of substitutions is formed, which is constructed by obtaining a multiplicative inverse element x-1 over the extended Galois finite field GF (28) and by performing an affine transformation y = M.x-1 ++ over a primitive Galois binary field GF (2 ). Variable inverse symmetric matrices are used as the M affinity transformation matrix, which are selected according to the value of the cyclic key, and the functional operations of cyclic shift and addition modulo 2, mixing and sliding coding are not fixed, but depend on the key state, and iterative processing by primitive cryptographic transformations occurs. in the following sequence: functional operations of cyclic shift and addition modulo 2 (ShiftRow), mixing (permutation), substitution (substitution), functional operations of sliding coding (SlidCode).

Description

The utility model belongs to the field of cryptographic information protection and can be used in encryption tools in information processing systems to expand their capabilities.

There is a known method of cryptographic transformation (1), which is based on the fact that the information sequence is presented in the form of 64-bit blocks, which are subject to iterative processing by primitive cryptographic transformations: permutation (repetition) using permutation blocks (P-blocks); substitution (zyB5iyshiop) using substitution blocks (5-blocks); functional operations of cyclic shift and addition modulo 2 using appropriate devices. Iterative processing consists in multiple execution of the same groups of transformations, which provide the necessary conditions for stability of cryptographic transformation: scattering (using P-blocks) and mixing (using 5-blocks) of information data.

The disadvantages of this method are: the fact that for the cryptographic transformation of information into a 5-block, a fixed matrix of substitutions is used, which does not allow to flexibly change the parameters of cryptographic processing and dynamically control the process of shuffling information data, as well as the fact that for the functional shuffling operation, fixed values of the shift parameters.

The closest to the proposed technical solution, chosen as the closest analog, is an improved method of cryptographic transformation |2), which is based on the fact that the information sequence is presented in the form of bit blocks, which are subject to iterative processing by primitive cryptographic transformations: shuffling (reptyshyop) using blocks mixing of cubes (ReptiyaZ3O blocks); substitution (5!Irziyshiop) using substitution blocks (5-blocks); functional operations of cyclic shift and addition modulo 2 (5pPShNOmMm) using appropriate devices. At the same time, the bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes) and as a 5-block form a variable three-dimensional matrix of substitutions, and it is constructed by obtaining the multiplicative inverse element x" over the extended finite Galois field CE(29) and by performing the affine transformation y-M :x"--rD over the primitive Galois binary field CE(2), while variable inverse symmetric matrices are used as the matrix M of the affine transformation, which

Zo is chosen according to the value of the cyclic key, and the functional operations of the cyclic shift are not fixed, but depend on the state of the key.

The disadvantages of the analogue are that for cryptographic transformation of information as a 5-block, a fixed substitution matrix acts, which does not allow to flexibly change the parameters of cryptographic processing and dynamically control the process of substitution of information data, and that for cryptographic transformation of information, the substitution parameters are fixed, and that that for the cryptographic transformation of information, the cyclic shift parameters are fixed.

The basis of a useful model is the task of creating a method of cryptographic transformation of information, which, due to the use of four three-dimensional cryptographic transformations (substitution, shuffling, cyclic shift and sliding coding), will make it possible to flexibly change the parameters of cryptographic processing and dynamically control the process of cyclic shift and addition according to module 2, shuffling and sliding coding of information data in three-dimensional space, and functional operations of cyclic shift and addition by modulo 2, shuffling and sliding coding are not fixed, but depend on the state of the key, and iterative processing by primitive cryptographic transformations occurs in the following sequence: functional operations of cyclic shift and addition by modulo 2 (ZpPiiNOm), shuffling (reptshaiiop), substitution (5!irviyshiop), functional operations of sliding coding (5iIiaSoave).

The problem is solved by the fact that the method of cryptographic transformation of information, which consists in the fact that the information sequence is presented in the form of bit blocks, which are subject to iterative processing by primitive cryptographic transformations: functional operations of cyclic shift and addition modulo 2 (ZPSHNOmM) using appropriate devices, substitution (5!yb5iyshiop) using blocks of substitutions (5-blocks); shuffling (repeating) with the help of cube shuffling blocks (P-blocks); functional operations of sliding coding (5iIiYa4Sode) - with the help of mixed Gray codes, in which, according to a useful model, the bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes) and as a 5-block form a variable three-dimensional substitution matrix, which is built by obtaining a multiplicative inverse element x over the extended finite Galois field CE(29) and by performing the affine transformation y-M'x"-p over the primitive binary Galois field CE(2), while variable inverse symmetric matrices are used as the matrix M of the affine transformation, which are chosen accordingly to the value of the cyclic key, and the functional operations of cyclic shift and addition modulo 2, shuffling and sliding coding are not fixed, but depend on the state of the key, and iterative processing by primitive cryptographic transformations occurs in the following sequence: functional operations of cyclic shift and addition modulo 2 ( 5PyNVoOm), mixing (reptiiaiiyop), substitution (vyr viyshiop), functional operations of sliding coding (51IiaSoavye).

The technical result that can be obtained when implementing a useful model consists in obtaining the ability to flexibly change the parameters of cryptographic processing of information data and dynamically control the process of cyclic shift and addition according to module 2, shuffling and sliding coding.

The method of cryptographic transformation of information is realized by the fact that the information sequence is presented in the form of 256-bit blocks, which are subject to iterative processing by primitive cryptographic transformations: functional operations of cyclic shift and addition modulo 2 (ZPISHNOMm) - with the help of appropriate devices, substitution (vyrviyshiop) with the help of blocks substitution (5-blocks); shuffling (reptshiiyayop) using cube shuffling blocks (P-blocks); functional operations of sliding coding (ZidSode) using mixed Gray codes. As a 5-block, there is a variable matrix of substitutions, which is constructed by obtaining a multiplicatively inverse element x over the extended finite Galois field CE(28) and by performing an affine transformation (I) over a primitive binary Galois field (СБ(2) while as a symmetric matrix M of the affine transformations use variable inverse symmetric matrices, which are chosen according to the value of the cyclic key, and the functional operations of cyclic shift and addition modulo 2, shuffling and sliding coding are not fixed, but depend on the state of the key, and the iterative processing by primitive cryptographic transformations occurs in the following sequence: functional operations of cyclic shift and addition by module 2 (ZpPIiNoOm), shuffling (reptiiaiop), substitution (zyiBziysiop), functional operations of sliding coding (51iaSoavye).

The cyclic key is generated from the encryption key using the key generation algorithm. The length of the cyclic key is equal to the length of the block. Cycle keys are generated from the encryption key using key expansion. The extended key is a linear array of 4-byte words. That is, at each iteration of the cryptographic transformation, a corresponding symmetric matrix M is used, which can be selected from a large set of inverse matrices with the help of a cyclic 4-byte key. This makes it possible to flexibly change the shuffling matrix in the process of cryptographic transformation and dynamically control the process of shuffling, substitution, cyclic shift and sliding coding of information data.

Depending on the stage of the round key, the parameter of shuffling, substitution, cyclic shift and sliding coding is selected by adding modulo 2 all bytes of the key, setting 1 in the lower digit of the result of addition (to form an odd value) and getting rid of the higher digit of the result of addition (remains 7 with 8 significant bits). The final value determines the amount of shift in the current round.

Thus, due to the use of variable inverse symmetric matrices and a variable (dependent on the round key) substitution function, it is possible to apply dynamically changing substitution matrices and annual values of sliding coding as a 5-block at each iteration of the cryptographic transformation of information, which makes it possible to flexibly change the parameters of cryptographic processing and dynamically control the process of cyclic shift and addition by module 2, shuffling and sliding coding of information data in three-dimensional space.

Sources of information: 1. "RGIRB5 ROV 46-3" EESEVAI IMEOVMATIOM RAEOSEBBIMY 5BIAMOAKOV ROVI SATIOM. RATA EMSAMRTIOM ZTAMOANVO (OE5) 1999 OKiobeg 25, radez 26. pEruLlymly. emeguzres.sot/MIZT/MIZT-RIRB/dompioaid. ryr"zres- GIR ROV 46-3.030171. rai 2. Patent of Ukraine for a utility model Me99696, IPC (p:09С 11/00 (2015.01). Method of cryptographic transformation of information / Bilenky A.Ya., Navrotskyi D.O.; applicant and the patent owner is the National Aviation University. - Mo c201404060; application 04/16/2014; published 06/25/2015, Mo 12-5 p.

Claims (1)

USEFUL MODEL FORMULA A method of cryptographic transformation of information, which consists in the fact that the information sequence is presented in the form of bit blocks, which are subject to iterative processing by primitive cryptographic transformations: functional operations of cyclic shift and addition by 60 module 2 (ZPSHNOmM) - with the help of appropriate devices, substitution (5!irviyshiop) - with the help of substitution blocks (5-blocks); shuffling (repeating) with the help of cube shuffling blocks (P-blocks); functional operations of sliding coding (5iiiSode) using mixed Gray codes, which is distinguished by the fact that the bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes) and as a 5-block form a variable three-dimensional matrix of substitutions, which are built by obtaining the multiplicative inverse element x" over by the extended finite Galois field CE(25) and by performing the affine transformation y-M'x"--8 over the primitive binary Galois field CE(2), while variable inverse symmetric matrices are used as the matrix M of the affine transformation, which are chosen according to the value cyclic key, and the functional operations of cyclic shift and addition modulo 2, shuffling and sliding coding are not fixed, but depend on the state of the key, and iterative processing by primitive cryptographic transformations occurs in the following sequence: functional operations of cyclic shift and addition modulo 2 (ZpPiНОm) , mixing (reptiiaiyop), substitution (5!ts051yiShiop), fun ctional operations of sliding coding (51st Soave).